Bibliography:
http://www.biography.com/people/leonardo-da-vinci-40396#synopsis
http://www.geniusstuff.com/blog/list/10-leonardo-da-vinci-inventions/
http://www.history.com/topics/leonardo-da-vinci
http://www.britannica.com/biography/Leonardo-da-Vinci
http://www.da-vinci-inventions.com/ideal-city.aspx
http://www.biography.com/people/leonardo-da-vinci-40396#synopsis
http://www.geniusstuff.com/blog/list/10-leonardo-da-vinci-inventions/
http://www.history.com/topics/leonardo-da-vinci
http://www.britannica.com/biography/Leonardo-da-Vinci
http://www.da-vinci-inventions.com/ideal-city.aspx